1. Field of the Invention
This invention relates generally to improved portable heaters used in relatively small enclosures. More particularly, the invention relates to a uniquely configured propane source infrared heater for use in enclosures such as small recreational enclosures, temporary work enclosures, or vehicles. Although the invention was designed for indoor areas, it will be appreciated that it has broader applications and may be advantageously employed in a wide variety of environments without departing from the scope of the invention.
2. Description of Related Art
Gas-fired portable heaters are well known in the art and are used in multiple environments. The heater typically includes a housing having a chamber. The housing has an inlet for receiving air into the chamber. Gas is introduced into the chamber to be mixed with the air in order to complete combustion and provide an infrared heating surface. A plenum directs the heat toward a mesh screen and evenly distributes it over the surface thereof. The overall goal in designing such a unit is to achieve a radiant surface that provides even, stable heating over the entire surface.
The use of such heaters is strictly regulated for outdoor only use due to the emission of carbon monoxide. Prior designs in existing portable units are subject to a wide variety of problems. Most importantly, the prior designs are not safe or certified to operate in small recreational enclosures such as tents, truck-caps, fishing huts, trailers, vans, etc. There are a few reasons why the devices found in the prior art are not adequate to perform in such environments. First, the portable heaters that exist today operate at a high pressure generally on the order of 12 psi. Specifically, the pressure from the propane tank through a regulator is necessarily high in order to achieve adequate gas and air flow. In addition to requiring high pressure, previous designs do not have the ability to pass strict combustion requirements at a high and low firing condition and at a reduced pressure. For example, a new standard developed for this product (CSA International 4.98 US) states that “the appliance shall not produce carbon monoxide in excess of 0.010 (100 ppm) percent in a room with no air changes occurring during combustion of the amount of gas necessary to reduce the oxygen content of the room to 18 percent by volume.” In addition, they do not possess an oxygen depletion system (“ODS”) (Capreci/Part No. 21500). These shortcoming's have prevented the portable heaters found in the prior art from adequately performing in small recreational and temporary work enclosures.
Existing portable units typically combust a fuel such as propane to generate heat. Propane tanks come in a variety of sizes such as a 1 pound tank that can be replaced when the propane fuel is fully consumed. To replace an empty propane tank with a full propane tank, existing heaters require the propane tank to be raised into the connection point of the heater in an upward direction from below to avoid contacting a protective structure that guards the connection between the fuel tank and the heater. In close quarters, this can be difficult to accomplish. As an alternative, the heater can be lifted to facilitate the replacement of an empty propane tank with a new tank. However, lifting the heater to install a replacement propane tank can be cumbersome, and difficult to do with one person.
Attempts have been made to alleviate at least some of the burdens associated with replacing an empty propane tank. Such attempts have typically revolved around a rotatable regulator that can be rotated in order to expose the connection point to establish a direct connection between the propane tank and the regulator. However, repeated rotation of the regulator can subject the regulator to damage from prolonged use, which in turn can cause an undesirable connection between the heater and the propane tank and hamper the ability of the heater to function properly.
Therefore, a need exists to provide a portable infrared heater capable of performing safely in small recreational enclosures and temporary work enclosures that can facilitate ready replacement of a fuel source.